Origin of conglomeratic limestone "Dokan conglomerate” in Dokan area, Kurdistan region, ne Iraq

الملخص EN

Thick succession of conglomeratic limestone (about 300 m thick) is exposed on right and left sides of Dokan reservoir and covers more than 40 Km2 of surface area.

It called "Dokan Conglomerate" in this study, which is not described and shown on any geological map, previously.

The Dokan conglomerate is indurate and weathering resistant, which mostly consists of blocks, boulders and gravels of Qamchuqa Formation, with some clasts of Kometan Formation, and at the upper part rare clasts of Pila Spi Formation can be observed.

The conglomerate is folded and in some place has more than 30 degrees, and angularly overlies the Kolosh, Shiranish, Kometan formations with more than 20 degrees difference in dip.

In other areas, the conglomerate shows, more or less equal dip with aforementioned formations.

The paleocurrent analysis revealed southwest, south, southeast direction for lower, middle and upper part of the conglomerate.

From indicating the origin of the pebbles of the conglomerate, the succession should be younger than Upper Eocene, due to the presence of clasts of Pila Spi Formation (Upper Eocene).

For finding the stratigraphic position and relation of the Dokan Conglomerate with other Tertiary unit, the surround areas were inspected.

The inspection was concentrated to the south of Dokan area, toward which the paleocurrent is directed.

To the southwest of Taq Taq Town, about 40 Km to the south of Dokan town, an equivalent of the conglomerate was found, which nearly consists of similar lithology, but with finer caliber and more rounded pebbles.

This conglomerate is very similar to the Bai Hassan (Upper Bakhtiary) Formation, which according to previous studies is exposed in nearby area.

Therefore, the Dokan Conglomerate is believed to be the equivalent of Bai Hassan Formation.